Why take a ‘Source to Sea’ approach to water impacts?

Here at Bemari we are big on interconnected water impacts.

However it can be difficult to help clients conceptualise how freshwater and marine water impacts are connected.

This need for greater corporate understanding of two is increasingly prescient, given that many businesses will need to conduct double materiality assessment that includes fresh- & marine-water impacts, as part of their CSRD disclosure.

This is why we love the Source to Sea (S2S) approach to water as it is an accessible, holistic framework for understanding freshwater and marine TOGETHER.

What is the S2S approach?

The S2S approach is grounded in the reality that what we do on land and in rivers, lakes and aquifers can have impacts further downstream along coasts and in the ocean... and vice versa.

The source to sea system

Understanding this interconnectivity is critical for holistically reducing business water impacts. As false binaries make it difficult to understand how direct impacts on freshwater may indirectly (but severely) impact marine ecosystems (+ coastal communities) and vice versa.

There are also shades of ecosystems between freshwater & marine which can get lost from the conversation when we create false binaries. Mangroves & salt marshes are a good example of in-between-y brackish ecosystems, which are highly endangered, highly impacted by business activities but don't fall neatly into the the 'freshwater' or 'marine water' categories.

3 examples of interconnected water impacts
  • Globally, only 1,000 rivers are responsible for nearly 80% of marine plastic pollution
  • Globally, saltwater intrusion of drinking water sources is a growing risk to coastal communities, due to upstream over-extraction & climate-induced sea-level rise.
  • Agricultural run-off & wastewater is the primary factor in creation 500 marine dead-zones (collectively covering an area greater than the UK). The majority of this pollution enters oceans via rivers.
A useful framework for businesses

What we particularly like about S2S, is that the approach includes practical frameworks to help businesses understand their impacts and also metrics for measurement. Below is an example of the 'key flow' framework, which outlines the six key flows that connect the source-to-sea system from land systems to open oceans.

Key Flow Framework

This is a highly useful schematic for businesses to start evaluating their impacts, across a value chain, as it provides clear impact hotspots. For example:

  • Where is your water usage impacting water flow?
  • Where is your aggregate usage impacting sediment flows?
  • Where are you contributing to pollution?
  • What are the ecosystem services you rely on and how are your business activities creating risk?

If you are already a IWRM or ICZM practitioner, we really recommend you read this article that outlines the synergies and tensions between the different approaches. Essentially S2S is complimentary, it just aims to  break down silos between IWRM, ICZM and open water management, to better reflect the realities of water.

Our only gripe with S2S, is that it hasn't yet properly embedded the socio-political elements of water, nor does it take into account social injustice and water.

However in the spirit of seeking solutions that are high accuracy & low precision, rather than low accuracy & high precision, we feel the best move forward is to better integrating social justice into S2S, rather than overlooking the approach, due to this current limitation. We will talk about the intersection of WASH and S2S in a future blog post.

If you would like to learn about how you can apply a Source to Sea approach to your business and how it can help you with CSRD, then please reach out at hello@bemari.co.uk

Written by Elspeth Alexander

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